As we often say at PolitiFact, words matter. And as we’ll see, terms such as secular and non-religious are key in evaluating this claim.

With an "action alert" sent Nov. 9, 2012, the Freedom From Religion Foundation asked its members to call on President Barack Obama not to utter "so help me God" when he takes the presidential oath for the second time.

The alert included this assertion:

"Secular Americans are the fastest-growing religious identification demographic in this country."

Secular is defined as "not overtly or specifically religious" and as "pertaining to worldly things or to things that are not regarded as religious." But scholars differ on who should be classified as secular.

With the January 2013 inauguration approaching, let’s see whether secular Americans, as the foundation flatly states, are the fastest-growing religious identification demographic.

The foundation

The Freedom From Religion Foundation describes itself as a nonprofit with more than 18,000 members that "works to educate the public on matters relating to non-theism and to promote the constitutional principle of separation between church and state."

The foundation is among groups that call for the elimination of "so help me God" in presidential inaugurations. "So help me God" is, in fact, not part of the presidential oath of office, and historian debate about whether George Washington used it. But the phrase has been added to the end of the oath by modern-day presidents, including by Obama during his first swearing-in in 2009.

In a letter to Obama, the Freedom From Religion Foundation amplified its claim, using non-religious in place of secular in telling the president:

"In 1990, 8 percent of Americans were non-religious. When you were elected in 2008, 15 percent of Americans identified as non-religious. Now that number is 20 percent."

The study utilizes the term nones -- Americans who identify themselves as atheist, agnostic, or having no religious preference.

Here’s some of the Trinity College data:

1990

2008

Est. # of People

Percentage

Est. # of People

Percentage

Catholic

46,004,000

26.2

57,199,000

25.1

Other Christian

105,221,000

60

116,203,000

50.9

Total Christians

151,225,000

86.2

173,402,000

76

Other religions

5,853,000

3.3

8,796,000

3.9

‘Nones’

14,331,000

8.2

34,169,000

15

Don’t Know/
Refused

4,031,000

2.3

11,815,000

5.2

Total

175,440,000

228,182,000

So, comparing 1990 to 2008, the percentages of Catholics and other Christians declined. The percentage of people identifying with a non-Christian religion rose, but the percentage of people categorized as nones rose even faster, nearly doubling.

Barry Kosmin, one of the study’s co-authors, said the Freedom From Religion Foundation’s claim is "not controversial" if secular is taken to mean not identifying with a particular religion.

Kosmin also estimated that the current nones figure is 15 to 17 percent, not the 20 percent that the foundation cited.

The higher figure comes from the Pew study, released in October 2012, which utilizes the term unaffiliated. The study found that nearly 20 percent of Americans do not identify with any religion -- up from 15 percent five years earlier -- even though more than two-thirds of the 20 percent say they believe in God.

Here’s some of the Pew data:

Religious affiliation

2007

2012

Christian

78%

73%

Other faith

4%

6%

Unaffiliated

15.3%

19.6%

Don’t know

2%

2%

So, like the Trinity College study, Pew found a decline in the percentage of Americans identified as Christian, an increase in those with a non-Christian designation and a larger increase in the unaffiliated category.

But there are some caveats from people involved in both studies.

Kosmin noted his study is different from Pew’s in that Pew’s unaffiliated definition includes some people who are regular churchgoers.

And Pew spokeswoman Jemila Woodson told us Pew does not state that any particular group is the fastest growing, partly because defining growth isn’t easy.

A wave of immigrants from Brazil, for example, could cause a significant increase in the U.S. Catholic population, while another group could experience a significant decline due to religious conversion, Woodson said. Growth "at a higher rate than all other groups doesn’t necessarily mean that people are joining this particular faith at a faster rate than all others," she said.

Other views

Two experts, Robert Glenn Howard of the University of Wisconsin-Madison and Patrick Carey of Marquette University in Milwaukee, told us the terminology used by Pew more accurately reflects where Americans are.

Howard, a specialist in contemporary religious belief, said the Freedom From Religion Foundation’s statement is basically on target in the sense that "people are increasingly moving away from claiming a specific religious affiliation for themselves.

"However, the majority of those are not ‘secular’ but instead see religion as important and describe themselves as either ‘religious’ or ‘spiritual,’" he said.

Carey, chairman of Catholic theology at Marquette, said that from the Pew study and others he follows, unaffiliated Americans are the fastest-growing segment in terms of religious identification.

But aside from atheists and agnostics, who make up a small portion of that group, it’s not correct to say that segment is secular or non-religious, he said.

We'll also note a news story about the Pew study, in which the national religion writer for Associated Press observed:

"Scholars have long debated whether people who say they no longer belong to a religious group should be considered secular. While the category as defined by Pew researchers includes atheists, it also encompasses majorities of people who say they believe in God, and a notable minority who pray daily or consider themselves ‘spiritual’ but not ‘religious.’

"Still, Pew found overall that most of the unaffiliated aren't actively seeking another religious home, indicating that their ties with organized religion are permanently broken."

Our rating

The Freedom From Religion Foundation said: "Secular Americans are the fastest growing religious identification demographic in this country." It also used the term non-religious in place of secular.

The statement is partially accurate, in that surveys identify unaffiliated Americans as the fastest-growing group. But the statement leaves out important details, namely that many Americans not affiliated with a particular religion are still religious.

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